Spark plug



Feb, 5 1924.

SPARK PLUG Filed July 5. 1921 (Trl-cmu Patented Feb. 5, 1924.

UNITED STATES 'oBY A. GoDwrN, or mammalian, Atalanta.

SPARK RLUG.

Anploation #led July 5, 1821.

To all whm, t may cav/n cern Be it known that I, Our A.. GonwrN, a citizen of they United States of America, residing at Birmingham, 11i the vCounty 0f Jefferson and State of Alabama, have invented certain new and useful Improvements in. Spark Plugs, of which the following is a specification.

My invention relates to an imprQYQUleIlt in spark plugs in which a stationary insulator is mounted in the plug shell and rovided with an axial opening exten ing therethrough for the reception of a priming tube forming one of 'the electrodes.

The most distinctive feature of my invention is the design of the insulator and of the tube to enable the carbon deposits to be blown out 'through the tube and to avoid the presence of pockets or shoulders behind which the oil or carbon will tend to collect and foul the plug.

A further feature of my invention releates to the construction of the nut forming a closure for the outer end of the tubular electrode.

My invention further comprises the novel details of construction and arrangements of parts, which in their preferred embodiment only are illustrated in the accompanying drawings, in which Fig. 1 is a plan view of the nut closure for the electrode tube.

Fig. 2 is a longitudinal vertical sectional view taken on the line 22 of Fig. 3.

Fi'g. 3 is a bottom view of the plug.

Similar reference numerals refer to similar parts throughout the drawings.

The plug comprises a shell 1 having a hor izontal body portion 2 and a threaded inner end 3 which carries one electrode or sparking terminal 4, which may be of any standard design. A porcelain or mica insulator 5 is mounted in the shell with packing rings 6 and 7 interposed so that when the flange 8 of the shell is swaged over the insulator is permanently and positively mounted and sealed pressure tight in position in the shell. The insulator has a longitudinal bore thercthrough adapted to receive a tubular electrode 9 which preferably has its body portion in the insulator' threaded to furnish a better grip for the cement which is utilized to seal it in place in the center bore of the insulator. The inner end 10 of the insulator is cylindrical in form and adapted to fit snugly into the bore in the inner end 3 of Serial No.. $82,346.

the shell. The bottom end of the insulator is provided with an upwardly tapering ref cess 11 and the lower end of the tube comes flush with the upper ,end of this taper re-` and is correspondingly tapered to avoid a shoulder. '1l-he tube is cut away to leave a segmental extension 12 which projects through the recess 11 and forms a sparking terminal disposed to @wat with. the sparking terminal 4. The upper end of the tube 9 extends above the electrode, and carries a nut 13, a terminal nut 1.4 and a closure nut 15 closed overhead and provided with a taper seat 16 adapted to co-act with the tapered end 1'7 of the tube to seat thereagainst and positively close the upper end of the tube. The nut 15 below its seat 16 is provided with lateral holes 18, which when the nu't is screwed up from the seat on the tube will have communication with the tube. The body of the nut 15 is knurled and has fast thereon a hard rubber knurled grip 19.

In ordinary use the sparking terminals 4 and 12 co-act in the normal way to produce the spark and the plug functions as in the case of present plugs, but when carbon or oil tend to collect in the lower end of the shell 3 or in the taper recess 11 in the insulator, it is only necessary 'to loosen the nut 15, whereupon an explosion of gases will blow all oil and carbon deposits out through the tube 9 and through the holes 18 or through the top of the tube if the nut 15 be entirely removed. The absence of any obstructions to the discharge of the gases and the carbon deposits with them is an important feature of my invention, there being no point at which carbon may tend to collect except behind the segment extension 12 of the sleeve, but as this itself is curved the tendency of the out rush of gases will be to sweep it clean. At any rate there will be no possibility of sufhcient carbon collecting about the extension 12 to foul its sparking end.

Should it be desired 'to prime the motor, this can be readily done through the tube 9 by removing the nut 15. The knurled grip 19 surrounding the nut 15 enables it to be operated without danger of electric shock.

This invention is not intended to be restricted in scope to the specific embodiments shown, but contemplates such modifications as come within the spirit and scope of the claims.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

l. In a spark plug, a shell havinga an in sulator mounted therein, the inner end of the insulator beingadapted to lit snugly in lthe bore at the inner end of the shell and having its inner end formed with an upwardly tapered recess, a tubular electrode having its lower end beveled to form a coutinuation of the taper of the recess and extending.)Y from the apex of said recess through the bore ot. the insulator and having,r a narrow integral segmental extension projectinol into said recess toform a sparking termina a sparking terminal on the shell adapted to eo-act with said insulator terminal, means to anchor the tube in the insulator, and means to close the open upper end of the tube.

2.`In a spark plug, a metallic shell havin'g a smooth bore extending of uniform diameter through its inner end, u sparkingl terminal on said shell, an insulator mounted in the shell with a cylindrical inner end adapted to fit snugly into said bore of the shell, the inner end of the insulator' having an upwardly tapering recess therein which rises from the bore so as to avoid'a substantial shoulder, a tubular electrode having its lower open end beveled to form a continua- 'tion oi said tapered recess and extending axially through and above the insulator, means to seal and anchor said electrode, and a sparking terminal extending from the inner end of the electrode below the taper recess and adapted t0 co-act with said sparking terminal on the shell, substantially as described.

In testimony whereof I affix my signature.

OBY A. GODWIN. Witness:

. Nome IVELei-I. 

